Artificial hand.



L. G. BARON.

ARTIFICIAL HAND.

APPLICATION men FEB. 2. \918.

Patented Nov. 26, 1918.

LOUIS G. GABON, OF TORONTO, ONTARIO, CANADA.

ARTIFICIAL HAND.

Specification of Letters Patent.

Application filed February 2, 1918. Serial No. 215,194.

To all whom it may concern:

Be it known that I, LoUIs G. CAnoN, of the city of Toronto, in the county of York, Province of Ontario, Canada, a citizen of the United States of America. have invented certain new and useful Improvements in Artificial Hands, of which the following is a specification. p

This invention relates to artificial hands of the type in which it is desired that the digits shall be capable of being flexed substantially to resemble the movements of the natural hand, and my object is to devise simple means for flexing and extending the dig ts and for releasably locking the fingers in flexed position.

I attain my object by means of the constru ti'ons hereinafter more specifically described and illustrated in the accompanying drawings in which Figure 1 is a front elevation, partly in section, of a hand constructed in accordance with my invention;

Fig. 2 a side elevation of the same partly in section; and

Fig. 3 a long tudinal section showing more particularly the hook pivoted in opposition to the fingers.

In the drawings like-numerals of reference indicate corresponding parts in the different figures. I V

1 is the hand. The wrist portion of the hand is formed as a hollow ball member 2 whereby it may be connected with a wrist member such as shown in my co-pending application No. 207335 filed December 15th, 1917.

The thumb 3 is pivoted at 4 to swing on an axis transverse of the palm of the hand whereby the thumb moves in opposition to the fingers. Its inner end is provided with a ratchet rack 5, which is engaged by a spring actuated dog 6 suitably fulcrumed within the hand and extending out through a suitable opening or slot in the hand. A coil spring 7 is located on the pivot pin of the thumb and is provided with arms, one of which engages the thumb and the other a suitable stationary part 8. This spring tends to move the thumb away from the fingers.

The fingers are provided with first, second and third joints. The first joints or knuckle members 9 are rigidly connected together and are pivoted on the hand by means of a pivot pin 10. The second and third jolnts 11 and 12 are independently pivoted as shown. The connected first joints are pro- Patented Nov. 2c, 1918.

one of which engages the worm and the other asuitable stationary part 16. This spring tends to rotate the worm to flex the united first finger joints, that is, to bend them toward the thumb. To operate the second ]0111i3s I provide for each finger a bell crank lever 17 pivoted on each first joint in front of the pivot pin 10. One arm of the bell crank lever extends into the hand and has a sliding connection therewith. Preferably a slot 18 .is formed in the arm of the bell cranklever which engages a pin 19 in the hand. The other end of each bell crank lever extends rearwardly and is pivotally connected with one end of a link 20 pivotally connected with the second finger joint in front of the pivot thereof. From the construction described it follows that when the first finger joints are rocked. each of the bell crank letending arm 21 is formed on each link 20.

Each of these arms is pivotally connected with a link 22, the other end of whi h is connected with the third finger joint at the front of its pivot. By partially rotating the worm 14, the fingers may thus be extended as shown in full lines in Fig. 2 or flexed as shown in dotted lines. The worm is part ally rotated to extend the fingers through the medium of a cable 31, which may be connected with any suitable operating means as well known in the art.

For my purposes it is desirable that the ends of the forefinger and thumb should cooperate in grasping an object, while at other times it may be necessary for the end of the thumb to pass the forefinger. I therefore hinge the end 23 of the thumb at 24 on the main part of the thumb. (Jo-acting shoulders 25 are formed on the parts of the thumb which prevent the end swinging too far in either direction.

As in the construction shown in the prior application hereinbefore referred to, I prefer to employ in the present hand a hook 26 which is located at the opposite side of the palm of the hand to the thumb. This hook works through a slot formed in the palm of the hand. so that it may be either swung up to the position shown in dotted lines in Fig. 3 or, when not required, swung down out of the way as shown in full lines. This hook is provided with a ratchet rack 27 concentric with its pivot or hinge pin 19 and with this rack engages a spring actuated dog 29, which dog has an arm 30 extending out through a hole or slot in the hand, by means of which it may be disengaged from the rack when necessary.

From the above description and drawings it will be seen that I have devised fingeroperating mechanism which is extremely simple and not liable to get out of order. It further possesses the advantage that, though moved to the fieXed position by a spring, the fingers will be locked in the flexed position through the medium of the worm and worm wheel until such time as the worm wheel is actuated to extend them. Perfect cooperation between the fingers and thumb and hook will also be obtained so that an desired objects may be securely grasped.

lVhat I claim as my invention is 1. In an artificial hand, the combination of a finger joint pivota 1 connected thereto; a bell-cranl' lever pivoted on the joint in front of the pivot thereof; a second finger joint pivoted on the first; a link pivotally connected at one end to said second joint in front of its pivot and at its other end to the adjacent end of the bell crank lever, the other ltl of the lever having sliding connection with the hand; and means for rocking the first joint on its pivot.

2. In an artificial hand, the combination of a finger oint pivotally connected thereto; a bell crank lever pivoted on the joint in front of the pivot thereof; a second finger joint pivoted on the first: a link pivotally connected at one end to said second joint in front of its pivot and at its other end to the adjacent end of the bell crank lever, the other end of the lever having a sliding connection with the hand; a third joint pivoted on the second; a link pivotally connected at one end to said joint; a rearwardly extending arm on the first mentioned link to which the other end of the second mentioned link is pivotally connected; and means for. rocking the first joint on its pivot.

3. In an artificial hand, the combination of a finger oint pivotally connected thereto; a bell crank lever pivoted on the joint in front of the pivot thereof; a second finger joint pivoted on the first; a link pivotally connected at one end to said second joint in front of its pivot and at its other end to the adjacent end of the bell crank lever, the other end of the lever having a sliding connection with the hand; and means for rocking the first joint on its pivot comp ising a worm wheel formed on the first finger joint; a worm journaled in the hand and meshing with the worm wheel.

4. Inan artificial, hand, the combination of a finger joint pivotally connected thereto; a. bell crank lever pivoted on the joint in front of the pivot thereof; a second finger joint pivot-ed on the first; a link pivotally connected at one end to said second joint in front of its pivot and at its other end to theadjacent end of the bell crank lever, the other end of the lever having a sliding connection with the hand; and means for rocking the first joint on its pivot comprising a worm wheel formed on the first finger joint; a worm journaled in the hand and meshing with the worm wheel; and a spring tending to rotate said worm to flex the finger.

5. In an artificial hand; the combination of a first finger joint pivotally connected thereto; a worm wheel for actuating said joint concentric with the pivot thereof; a worm journaled in the hand and. meshing with the worm wheel; a second finger joint pivoted on the first; and means whereb the rocking of the first finger joint on its pivot rocks the second in the same direction.

Signed at Toronto. Canada, this 23rd (lay of January, 1918.

LOUIS G. GABON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents,

Washington. D. 0. 

